Sponsored

392 squeaks after every start

cook03tj

Well-Known Member
First Name
Tim
Joined
May 4, 2021
Threads
4
Messages
50
Reaction score
92
Location
CA
Vehicle(s)
'42 GPW; '21 Rubicon 392 (Sold: '85 XJ; '03 TJ)
We got our 392 in May and after every start is squeaks. the squeak goes away after a few seconds depending on the last time it was driven, it squeaks the longest on a cold start. I have taken it into the dealership twice and they are telling me now it is a known issue that is designed to happen. They say it has to do with the performance exhaust letting out pressure at the valve, they said its supposed to do that. I don't believe its supposed to make that noise. Does anyone else have this noise?
Sponsored

 

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
444
Reaction score
907
Location
Colorado
Vehicle(s)
Too Many
Mine does the same thing. Almost sounds like a belt noise. Is definitely underneath though. Exhaust noise (leak\whistle) is what I come up with also. Not going to waste the time taking it to dealer though. Having way too much fun with it. I am sure you also found that if revved up it goes away quickly. Was a little concerned at first, yea it is a little annoying, but then said heck with it. LOL

Sam
 
OP
OP
cook03tj

cook03tj

Well-Known Member
First Name
Tim
Joined
May 4, 2021
Threads
4
Messages
50
Reaction score
92
Location
CA
Vehicle(s)
'42 GPW; '21 Rubicon 392 (Sold: '85 XJ; '03 TJ)
Mine does the same thing. Almost sounds like a belt noise. Is definitely underneath though. Exhaust noise (leak\whistle) is what I come up with also. Not going to waste the time taking it to dealer though. Having way too much fun with it. I am sure you also found that if revved up it goes away quickly. Was a little concerned at first, yea it is a little annoying, but then said heck with it. LOL

Sam
At least I'm not the only one! A belt noise is exactly what I thought it was too at first. Thank you!
 

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
444
Reaction score
907
Location
Colorado
Vehicle(s)
Too Many
I have to admit it took a while to come up with that conclusion though. No, it really should not make the noise, but it is not hurting anything at all.


Sam
 

Outrun

Well-Known Member
Joined
Feb 15, 2019
Threads
9
Messages
915
Reaction score
1,408
Location
PNW
Vehicle(s)
2021 392XR
Anyone have video of the sound?
 

Sponsored

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
444
Reaction score
907
Location
Colorado
Vehicle(s)
Too Many
I don't. Just imagine a very erratic belt squeal. Sounds just like that. There are days mine does not even do it. Other days worse than others. No real rhyme or reason, except much more prevalent when first started. Always goes away after a short bit.

Sam
 

Outrun

Well-Known Member
Joined
Feb 15, 2019
Threads
9
Messages
915
Reaction score
1,408
Location
PNW
Vehicle(s)
2021 392XR
I don't. Just imagine a very erratic belt squeal. Sounds just like that. There are days mine does not even do it. Other days worse than others. No real rhyme or reason, except much more prevalent when first started. Always goes away after a short bit.

Sam
Interesting. And the valve is vacuum actuated?
 

Monster1926

Well-Known Member
First Name
Steven
Joined
Jul 30, 2021
Threads
3
Messages
585
Reaction score
1,129
Location
Fort Wayne
Vehicle(s)
2021 Silverado 2500HD midnight
I had a focus RS and the valves would move back-and-forth to knock the carbon off so they didn’t get stuck. It might be what your hearing. Post a video if you can?
 

Jeepmarkjl

Well-Known Member
First Name
Mark
Joined
Apr 2, 2018
Threads
35
Messages
806
Reaction score
1,752
Location
Chicago
Vehicle(s)
2021 Wrangler JLU Rubicon
Occupation
Marketing
That squeek means your McCluckens diffusion valves are already shot which means then the Schmerkler stems will eventually explode catastrophically. This essentially means the JEEP is a total loss and these items are not covered under warranty. So instead of a total loss I’d be willing to take the Jeep off your hands for $2-3K. It’s a win win. Kinda Sorta.
 

Sponsored

Higgs Boson

Active Member
Joined
Jun 30, 2021
Threads
0
Messages
27
Reaction score
40
Location
Texas Hill Country
Vehicle(s)
2021 Rubicon
The mopar v8 cold start squeak is actually common across the 392s and hellcat engines. I have a TRX and all the guys complain about the same noise.

jeep dealers all call it normal and due to the manifold design. cold start changes the cam and spark timing so i have a feeling it has to do with combustion events occuring late to help warm the cats up combined with the way the exhaust manifold is apparently designed creating this anomaly.

I wonder if headers eliminate this sound.
 

WIJLU

Well-Known Member
First Name
Eric
Joined
Jun 27, 2018
Threads
4
Messages
78
Reaction score
92
Location
Wisconsin
Vehicle(s)
2023 392 XR
It's even listed as a know issue in the small "392 specific" owners manual.
 

SSWIM

Well-Known Member
First Name
Sam
Joined
Jun 24, 2020
Threads
2
Messages
444
Reaction score
907
Location
Colorado
Vehicle(s)
Too Many
It's even listed as a know issue in the small "392 specific" owners manual.

Really? Do tell. I just looked through the 392 supplement and did not see a thing. Only thing said about any distinct exhaust sound was when under "torque reserve". This is not the "tick" that is addressed either.


Sam
 

WIJLU

Well-Known Member
First Name
Eric
Joined
Jun 27, 2018
Threads
4
Messages
78
Reaction score
92
Location
Wisconsin
Vehicle(s)
2023 392 XR
The "tick" at start up is what I was referencing...and what I hear on mine.
 
 



Top